机械结合面接触刚度建模新方法  

A New Method for Modeling Mechanical Joint Surface Contact Stiffness

作　　者：李玲[1] 王晶晶 裴喜永[1] 褚崴[1] 蔡安江[1] LI Ling;WANG Jingjing;PEI Xiyong;CHU Wei;CAI Anjiang(School of Mechanical and Electrical Engineering,Xi’an University of Architecture and Technology,Xi'an 710055)

机构地区：[1]西安建筑科技大学机电工程学院,西安710055

出　　处：《机械工程学报》2020年第9期162-169,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51975449);陕西省自然科学基金(2018JM5066)资助项目。

摘　　要：建立精确、有效的结合面接触刚度模型是进一步开展机床整机动力学建模与分析的基础。提出了一种新的弹性接触刚度模型,该模型考虑基体变形的同时,对GREENWOOD和WILLIAMSON提出的粗糙表面微观接触模型(GW模型)进行了修正。为分析基体对接触变形的影响,首先建立含有基体的单个微凸体接触模型,并基于HERTZ接触理论,获得结合面的接触参数;然后,通过引入三角分布函数和解决GW模型在模拟微观接触行为中存在的问题,建立了新的弹性接触刚度模型,并揭示了分布函数、基体变形以及表面粗糙度对结合面接触特性的影响规律。研究表明:三角分布函数能有效地表征表面微凸体高度分布;基体变形的影响是由基体和微凸体相互作用引起,随着法向载荷的增大而明显;表面粗糙度是影响接触刚度的主要因素,相同载荷下,表面粗糙度越大,接触变形越大,接触刚度越小。Establishing an accurate and effective joint contact stiffness model is the basis for further modeling and analysis of machine tool dynamics characteristics.A new elastic contact stiffness model is proposed,which considers the bulk substrate deformation and modifies the Greenwood and Williamson microcontact model(GW model)of rough surfaces.In order to analyze the influence of the bulk substrate on the contact deformation,a single asperity contact model containing the bulk substrate is first established,and the contact parameters of the joint surface are obtained based on the Hertz contact theory.Then,the new elastic contact stiffness model is proposed by introducing a triangular distribution function and making up for the defects of the GW model.The effects of distribution function,bulk substrate deformation and surface roughness on the contact characteristics of the joint surface are analyzed.The research shows that the triangular distribution function can effectively characterize asperity heights distribution.The influence of the bulk substrate deformation is caused by the interaction between the bulk substrate and the asperity,which is obvious as the normal load increases.In addition,surface roughness is the main factor affecting the contact stiffness.When the joint surface is applied with the same load,the surface roughness is larger,the contact deformation is larger,and the contact stiffness is smaller.

关 键 词：机械结合面 基体变形 三角分布 修正GW模型 接触刚度 

分 类 号：TG502[金属学及工艺—金属切削加工及机床]